The present invention relates to an occupant protection device for protecting an occupant at the time of a collision of a high-speed moving device, and, more particularly, to an occupant protection device including an airbag and a knee bag.
In order to protect an occupant at the time of an emergency, such as a collision of a vehicle, a driver-seat airbag, a passenger-seat airbag, a leg-protecting knee bag, or the like is provided in the vehicle.
The driver-seat airbag is provided at a steering wheel, and a passenger-seat airbag is primarily provided at an interior panel, such as an instrument panel. The knee bag is provided at, for example, a glove box or an interior panel, disposed in front of legs of the occupant.
The airbag and the knee bag are both covered in a folded state. At the time of an emergency, such as a collision of a vehicle, an inflator supplies gas into the airbag and the knee bag to inflate them. The cover is removed as being pushed by the expanding airbag and the knee bag, so that the airbag and the knee bag expand in front of the occupant.
An object of the present invention is to provide an occupant protection device to adequately protect the occupant by combining an airbag that expands in front of an upper half body of the occupant and a knee bag that expands in front of legs of the occupant.
Another object of the present invention is to provide an occupant protection device to adequately restrict a forward movement of a lumbar part of the occupant by an airbag.
A further object of the present invention is to provide an occupant protection device to restrain the occupant earlier by expanding an airbag in front of the occupant even if an inflator has a small output.
Further objects and advantages of the invention will be apparent from the following description of the invention.
An occupant protection device of the present invention includes an airbag that expands in front of an upper half body of a seated occupant and a knee bag that expands in front of occupant""s legs. A top end of an expanded knee bag is positioned at least 50 mm above a bottom end of an expanded airbag.
In such an occupant protection device, the top end portion of the expanded knee bag and the bottom end portion of the expanded airbag are placed and overlapped at front and back with respect to each other.
Therefore, for example, it is possible to construct the airbag such that the bottom end portion thereof moves into an area between the top end portion of the expanded knee bag and the occupant to restrict the bottom end portion of the airbag from moving back when the occupant pushes the airbag.
As a result, it is possible to adequately restrict a forward movement of the lumbar part of the occupant by the airbag. The space between the top end portion of the expanded knee bag and the occupant is smaller than a space that is provided when the knee bag is not provided. Therefore, by completing the expansion of the knee bag earlier than the expansion of the airbag, even if an inflator for expanding the airbag has a small output, it is possible to restrain the occupant by sufficiently expanding the airbag.
In the present invention, a vent hole may be provided in the knee bag that comes into contact with the expanded airbag. When such a structure is used, it is possible to maintain a gas pressure inside the knee bag at a relatively high value for a long period of time to restrict the gas in the knee bag from flowing out from the vent hole after the vent hole of the knee bag is covered by the airbag. Until the vent hole is covered by the airbag, the gas inside the knee bag flows out from the vent hole, so that a shock exerted on the legs of the occupant is sufficiently absorbed.